Anonymous3 days ago
A wave of large-scale neuroimaging studies since 2024 has produced contradictory findings about cannabis and brain structure, with some showing reduced white matter integrity and cortical thinning while others find larger brain volumes and better cognition in users. The largest study to use genetic causal analysis found no evidence that cannabis directly causes the observed brain differences, raising fundamental questions about decades of prior research and its relevance to the ongoing expansion of legal cannabis markets.